Remote oil filter

hello again folks, can i pick your brains some more?

i want to run a remote oil filter on a 40 EL stroker motor, and am curious as to whether there are any particularities i need to be aware of with doing this on a knucklehead or whether it's a generally bad idea all around.

the one i'm thinking about running is this one:
http://store.summitracing.com/partdetai ... toview=sku
but i am wondering if this is ok if i use fittings to adapt the 1/2" port size down to the correct size for the oil lines. also what size oil lines do you guys recommend for knucks? 3/8"? 1/4"?

would it be better to buy an oil filter mount with 3/8" ports?

thanks in advance!
-dan

Howdy Dan,

I've run a wide variety of add-on oil filters on Knuckles, Pans, Shovels, and iron-head Sportsters over the years and they all worked fine. I've used both 3/8" and 5/16" lines. The only cautions I'd make are to install the filter on the return line between the pump and oil tank, and make sure you've got the inlet and outlet hooked up correctly. Some years ago one of my mechanics built a generator/altenator motor with a Pan top end; we machined an aluminum adapter plate to bolt to the generator mount and set it up for a Ford truck spin-on filter, about the same length and diameter as the generator would have been. We hooked the oil lines up reversed, which is a problem because automotive filters are made with an anti-reversionary valve in them so the oil will only pass in one direction. He cranked the Pan up and took it for a spin around the block. As he pulled back into the shop, where a crowd of well-wishers was gathered to congratulate him on the maiden run of his new scoot, the oil filter exploded, showering everyone with warm oil. We straightened out the oil lines and the set up has been working without a hitch for twenty-some years now.

--- Randall

Randall:

Have you run an automotive type filter on a knuck with the oem pump (re: low volume/low pressure)? I have always been concerned with the lower output pump getting the oil through an auto type filter effectively. Any comments?

Brent

Hey Brent,

I have run spin-on filters on at least one Knucklehead with the OEM pump that I can recall. I have set up several Pans with cast iron pumps that way and more Sportsters than I can recall.

I have always primed the oil pump and kicked the bike through until I had oil coming out the return line in front of the filter before firing up the engine. I then check for oil flow coming out the return line on the other side of the filter (ever since we blew up the truck filter on the Pan). It takes a little longer for the flow to begin with a large capacity automotive filter than with a OEM cartridge filter. If there is no oil coming out of the filter then you have a problem and must sort it out before putting the bike on the street. The only problem I've ever had with add-on oil filters was with the gen/alt Pan referenced above and that was because we made the filter adapter at the shop and weren't aware that automotive filters would only flow oil in one direction. Most add-on filter units have in/out clearly marked, something we did to our adapter once we realized our mistake (and wiped the oil out of our eyes).

--- Randall

sounds great. thanks for the information guys, it helps out a lot!

-dan